Ultrasound has been used to stimulate individual brain cells in a worm. If the technique works in mice, it could be a less invasive way of studying specific neurons.

Neuroscientists currently implant probes into animal brains to stimulate cells that have been engineered to become sensitive to light. Sreekanth Chalasani at the Salk Institute for Biological Studies in La Jolla, California, and his colleagues instead introduced a pressure-sensitive protein, TRP-4, into neurons in the nematode Caenorhabditis elegans. They then put the worms in a Petri dish that was partially submerged in a water bath and sent a short burst of ultrasound into the dish, delivering mechanical signals to TRP-4 to activate certain neurons.

By adding the TRP-4 protein into neurons with different functions, the researchers were able to make free-crawling worms reverse direction, stop reversing or make more-frequent sharp turns in response to a brief pulse of ultrasound.

Nature Commun. 6, 8264 (2015)